If you are having trouble cutting a straight line try clamping a piece of thick flat bar to the metal and run the torch tip along it, if you want a dedicated "burn bar" grind a 45 degree angle on the bottom edge so the slag wont cause the tip to jump might consider a handle from some 1/2" round. I put a 1" spring on mine then bent the ends down about 6" keeps from burning my hand from heat transfer. I used about 2' of 3/4" F B 3" wide. The heavy bar doesn't move. Clean up isn't to bad with a good straight cut.

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